add API to dispatch native event

packages/react-native-fantom/src/__tests__/Fantom-itest.js

@@ -14,9 +14,15 @@ import 'react-native/Libraries/Core/InitializeCore';
 
 import type {Root} from '..';
 
-import {createRoot, runTask} from '..';
+import {
+  createRoot,
+  dispatchNativeEvent,
+  runOnUIThread,
+  runTask,
+  runWorkLoop,
+} from '..';
 import * as React from 'react';
-import {Text, View} from 'react-native';
+import {Text, TextInput, View} from 'react-native';
 import ensureInstance from 'react-native/src/private/utilities/ensureInstance';
 import ReactNativeElement from 'react-native/src/private/webapis/dom/nodes/ReactNativeElement';
 
@@ -369,4 +375,39 @@ describe('Fantom', () => {
       });
     });
   });
+
+  describe('runOnUIThread + dispatchNativeEvent', () => {
+    it('sends focus event', () => {
+      const root = createRoot();
+      let maybeNode;
+
+      let focusEvent = jest.fn();
+
+      runTask(() => {
+        root.render(
+          <TextInput
+            onFocus={focusEvent}
+            ref={node => {
+              maybeNode = node;
+            }}
+          />,
+        );
+      });
+
+      const element = ensureInstance(maybeNode, ReactNativeElement);
+
+      expect(focusEvent).toHaveBeenCalledTimes(0);
+
+      runOnUIThread(() => {
+        dispatchNativeEvent(element, 'focus');
+      });
+
+      // The tasks have not run.
+      expect(focusEvent).toHaveBeenCalledTimes(0);
+
+      runWorkLoop();
+
+      expect(focusEvent).toHaveBeenCalledTimes(1);
+    });
+  });
 });

packages/react-native-fantom/src/index.js

@@ -14,6 +14,8 @@ import type {
 } from './getFantomRenderedOutput';
 import type {MixedElement} from 'react';
 
+import ReactNativeElement from '../../react-native/src/private/webapis/dom/nodes/ReadOnlyNode';
+import {getShadowNode} from '../../react-native/src/private/webapis/dom/nodes/ReadOnlyNode';
 import * as Benchmark from './Benchmark';
 import getFantomRenderedOutput from './getFantomRenderedOutput';
 import ReactFabric from 'react-native/Libraries/Renderer/shims/ReactFabric';
@@ -100,7 +102,7 @@ export function scheduleTask(task: () => void | Promise<void>) {
 let flushingQueue = false;
 
 /*
- * Runs a task on on the event loop. To be used together with root.render.
+ * Runs a task on the event loop. To be used together with root.render.
  *
  * React must run inside of event loop to ensure scheduling environment is closer to production.
  */
@@ -115,6 +117,14 @@ export function runTask(task: () => void | Promise<void>) {
   runWorkLoop();
 }
 
+/*
+ * Simmulates running a task on the UI thread and forces side effect to drain the event queue, dispatching events to JavaScript.
+ */
+export function runOnUIThread(task: () => void) {
+  task();
+  NativeFantom.flushEventQueue();
+}
+
 /**
  * Runs the event loop until all tasks are executed.
  */
@@ -139,6 +149,11 @@ export function createRoot(rootConfig?: RootConfig): Root {
   return new Root(rootConfig);
 }
 
+export function dispatchNativeEvent(node: ReactNativeElement, type: string) {
+  const shadowNode = getShadowNode(node);
+  NativeFantom.dispatchNativeEvent(shadowNode, type);
+}
+
 export const unstable_benchmark = Benchmark;
 
 type FantomConstants = $ReadOnly<{

packages/react-native/Libraries/__tests__/__snapshots__/public-api-test.js.snap

@@ -10917,8 +10917,10 @@ interface Spec extends TurboModule {
     devicePixelRatio: number
   ) => void;
   stopSurface: (surfaceId: number) => void;
+  dispatchNativeEvent: (shadowNode: mixed, type: string) => void;
   getMountingManagerLogs: (surfaceId: number) => Array<string>;
   flushMessageQueue: () => void;
+  flushEventQueue: () => void;
   getRenderedOutput: (surfaceId: number, config: RenderFormatOptions) => string;
   reportTestSuiteResultsJSON: (results: string) => void;
 }

packages/react-native/ReactCommon/react/nativemodule/dom/NativeDOM.cpp

@@ -10,6 +10,7 @@
 #include <react/renderer/dom/DOM.h>
 #include <react/renderer/uimanager/PointerEventsProcessor.h>
 #include <react/renderer/uimanager/UIManagerBinding.h>
+#include <react/renderer/uimanager/primitives.h>
 
 #ifdef RN_DISABLE_OSS_PLUGIN_HEADER
 #include "Plugins.h"

packages/react-native/src/private/specs/modules/NativeFantom.js

@@ -26,8 +26,13 @@ interface Spec extends TurboModule {
     devicePixelRatio: number,
   ) => void;
   stopSurface: (surfaceId: number) => void;
+  dispatchNativeEvent: (
+    shadowNode: mixed /* ShadowNode */,
+    type: string,
+  ) => void;
   getMountingManagerLogs: (surfaceId: number) => Array<string>;
   flushMessageQueue: () => void;
+  flushEventQueue: () => void;
   getRenderedOutput: (surfaceId: number, config: RenderFormatOptions) => string;
   reportTestSuiteResultsJSON: (results: string) => void;
 }